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McKenney" , Metin Kaya , Xuewen Yan , Thomas Gleixner , "Daniel Lezcano" , Suleiman Souhlal , kuyo chang , hupu , References: <20251030001857.681432-1-jstultz@google.com> <20251030001857.681432-9-jstultz@google.com> Content-Language: en-US From: K Prateek Nayak In-Reply-To: <20251030001857.681432-9-jstultz@google.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-EOPAttributedMessage: 0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: SA2PEPF000015CD:EE_|SA5PPF530AE3851:EE_ X-MS-Office365-Filtering-Correlation-Id: 5c261cf1-fe37-4b13-637b-08de183ac8d1 X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0;ARA:13230040|7416014|376014|82310400026|1800799024|36860700013; X-Microsoft-Antispam-Message-Info: =?utf-8?B?VDR5ZWpaaG0wdE9lRUFHM0hFcE9zckliL0k3ZGV3TTRQemJrVzlLYjhNcy9a?= =?utf-8?B?aitWNHFmc2NRQUdBTnlWVmYwOTFxRmRSSEdPUWZ1ZUdYTXNhd1VzYmViaTBI?= =?utf-8?B?eml1dDFwMmVKVm14Qk1nMTlacWVxdWQzQnVRZ1ZnemNkY1JvMVF1cXVjYm1Z?= =?utf-8?B?UVZHZFArTVVBd3VHejJXdnNoZTNScmVWMTAxSW04YzJ1cVY3OVFGMVlHVjll?= =?utf-8?B?cHRaUWNhTmpPb0d3T3NNalRraXZxZnprcG1DamtzOFpUYVhIL1BZdEFuMHph?= =?utf-8?B?emtTYk5VaUIzNENqMFBMUWFmalgxTXk1NHZGd29FYXFadm1vNCt3YysyWkJM?= =?utf-8?B?V29IeEM3WlI1NzA4SzdjemFGQXhQRnhyYml0dXVWM2o3cDJUaExRMm5Kb2V5?= =?utf-8?B?Qjl4VktEUGUyVjUwYUZ2SkdoUFpEWHEwMG1ZaTlaOEFJaXBDTEV5RElPcEQx?= =?utf-8?B?NHlNQTk0eE9NZkppNEE0b09JV3RqVVNqNXBDNzFHZjZPaFgwS1B2QVducFJJ?= =?utf-8?B?MXBsV0NqcHRaTEJxNWk2VlZGcDNHUmRRUEdCWVRVSmpoc2pmdDcxZDYrR29n?= =?utf-8?B?TE9KcEc5TXpPR3g5djJJdHBoNkdyOFdML1dJWEM0Rm9kM3Z3ckxUcGNIbmVt?= =?utf-8?B?aUxpMFJUSThnOXM0QnVPcER1UWpGYlYxSkdhUWk3TGxnWUIrdEVyL2hqN2dV?= =?utf-8?B?V0FpUm9LZFI3VysxamV5VTN2RVk1M2V4Q1BtclNjdk9GeXpJbFc4YVVyY1l4?= =?utf-8?B?c2ozdnhiYU5nQlFDVEVqTkxCbjlZekI1MThaUndzNm5FdVdlcHNKNDU1VFFN?= =?utf-8?B?NHdnRmtUTUhTVjRXYnBUS1kwRmRvSDErdVVGTm53eE9xNnpoYjFSQ1Jtcm1M?= =?utf-8?B?NDU1bTlDUzJ6eE9yYi84K0tBbngxK0EwTmh1cGttM2x6OVlpTGEwR2ZvUkQr?= =?utf-8?B?T25lRHQzeVAyOHZrK243cFUwOGxVUWFuWXlHUVZCdUJ5QVg5UW1OdGowL1o0?= =?utf-8?B?V1h1SDlLbm5aWjFZUnZFbDBCYlQ3cFlLaTQweXV1VjdEUmFoZjhEeUhyMEh6?= =?utf-8?B?MUt1TThCb3grSkI5dTVzOHorZFJEbjNNR1BwS0hCMTdHOEJpQmdDZmF6YThC?= =?utf-8?B?aVE3WXN2SEpvU3A2M3dpNEV1d1k1ZXVYbEluRzNpTkxoVXFFSTZJcmdMaFg5?= =?utf-8?B?TFBsLzBJQ1ZHWUFGWG9Tc3oyb0kvRTFFeEVnZXZZZ0traDAzUXpzb1JhSFNM?= =?utf-8?B?eTlGc3U5bjI4WnRtVVJLdE1pMnNEVGlpMExaZHc3TUlvR0UrUHlOemlmTzhi?= =?utf-8?B?ajJzUnFRSjg3TFVsR2x6M21rOHlrajdvNG9zVDdSdXN0MEM5STRtc3FDRFcr?= =?utf-8?B?QnZBSnBaN0ZPZy9OVUtMOE9Ub1ZYd3VvbWRVNVNxMEhsa1VDNzIyRCtpK0d6?= =?utf-8?B?bFVpNkUwV1ZmRUJaWkV2dWJZTlRyV3FsbnBTdWxhM2NhYVUzMGY2dEcwZ0hM?= =?utf-8?B?WHlFZnBLYXAwTG1yK3dVSEtIT3lzOW1XN3BILzhGQld4OXRDbFFIOFRxL2xL?= =?utf-8?B?TUxrOEJyOXFmc21JSXAxUjNHcE5CQzJOdTkxNHhVaEJOck8rNUx3SjRlV21T?= =?utf-8?B?WnBBSFJhdFhvNnpnVkdvM1IrUXA4SC9NN3RmazRJQ3lFcjdJSnBsZ1A5ZnVI?= =?utf-8?B?NVNUYnBHTVV4clJCTmlvaHMzOUlidkRpTS9UM2lwQ29aSjdlMW1xOFdheU5a?= =?utf-8?B?d0c4WFptZlR2YllzeWlGNmtjMGh2MEorSDIyNDh5dVp2UC85OTYxTzU5c1Fa?= =?utf-8?B?OWR3QnRRYXg1VTRGSlFJN0J4TUNObnNZZGgzdG5xSURmRE5INUxrb1gzVVJC?= =?utf-8?B?L3NzbUtQU2h4NStJbVRpWC85Vjh2a0RndURhTkVVOFQ1cHVkdHliUkZUTEkz?= =?utf-8?B?ejBMc3JIUHRuTnNZeUNsUXRvNE9tYzh5eFZqTGM5a2wvT3hyQllXazFrSFF1?= =?utf-8?B?Qk9ZTTcrcytGUjg3QjJuOURRRFRUUFhDMk0rOHZZVXZ5eklYZ25oZUE1aDQw?= =?utf-8?B?L3R6TC9HMG5UWUVsYy9rSG1aa0Z1SmFJSEdlVXJtMHQxTGJxbXBYSFdoVTFS?= =?utf-8?Q?Za4c=3D?= X-Forefront-Antispam-Report: CIP:165.204.84.17;CTRY:US;LANG:en;SCL:1;SRV:;IPV:CAL;SFV:NSPM;H:satlexmb07.amd.com;PTR:InfoDomainNonexistent;CAT:NONE;SFS:(13230040)(7416014)(376014)(82310400026)(1800799024)(36860700013);DIR:OUT;SFP:1101; X-OriginatorOrg: amd.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 31 Oct 2025 05:03:08.8883 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 5c261cf1-fe37-4b13-637b-08de183ac8d1 X-MS-Exchange-CrossTenant-Id: 3dd8961f-e488-4e60-8e11-a82d994e183d X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=3dd8961f-e488-4e60-8e11-a82d994e183d;Ip=[165.204.84.17];Helo=[satlexmb07.amd.com] X-MS-Exchange-CrossTenant-AuthSource: SA2PEPF000015CD.namprd03.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: SA5PPF530AE3851 Hello Peter, John, On 10/30/2025 5:48 AM, John Stultz wrote: > @@ -958,7 +964,34 @@ static noinline void __sched __mutex_unlock_slowpath(struct mutex *lock, unsigne > > raw_spin_lock_irqsave(&lock->wait_lock, flags); > debug_mutex_unlock(lock); > - if (!list_empty(&lock->wait_list)) { > + > + if (sched_proxy_exec()) { > + raw_spin_lock(¤t->blocked_lock); > + /* > + * If we have a task boosting current, and that task was boosting > + * current through this lock, hand the lock to that task, as that > + * is the highest waiter, as selected by the scheduling function. > + */ > + donor = current->blocked_donor; > + if (donor) { Any concerns on new waiters always appearing as donors and in-turn starving the long time waiters on the list? > + struct mutex *next_lock; > + > + raw_spin_lock_nested(&donor->blocked_lock, SINGLE_DEPTH_NESTING); > + next_lock = __get_task_blocked_on(donor); > + if (next_lock == lock) { > + next = donor; > + __set_task_blocked_on_waking(donor, next_lock); > + wake_q_add(&wake_q, donor); > + current->blocked_donor = NULL; > + } > + raw_spin_unlock(&donor->blocked_lock); > + } > + } -- Thanks and Regards, Prateek